On 26 December 2004, a 1,200-km length of seafloor boundary between the India Plate and Burma microplate ruptured in the Sumatra-Andaman earthquake. This earthquake was one of the five largest earthquakes of the past century and the largest in the past four decades. The Sumatra-Andaman earthquake is the first large tsunamigenic event and the first with an estimated Mw ≥ 9 to be recorded by the Global Seismographic Network (GSN; Figure 1; Butler et al., 2004), as well as the observatories of the broader Federation of Digital Seismographic Networks (FDSN; Dziewonski, 1994). Earthquakes with Mw...